[Identity] Support concurrently running commands with MSAL

## Description

The current management of file `.azure/accessTokens.json` is not thread-safe, which leads to issue #1347, #8766, #9427.

[microsoft-authentication-extensions-for-python](https://github.com/AzureAD/microsoft-authentication-extensions-for-python) already uses [portalocker](https://pypi.org/project/portalocker/) to handle concurrent accesses:

https://github.com/AzureAD/microsoft-authentication-extensions-for-python/blob/35641c37de1f0bbb214627769e5847e74808ad55/setup.py#L28-L29

```py
"portalocker~=1.6;platform_system=='Windows'",
"portalocker~=1.0;platform_system!='Windows'",
```

With the current [integration with MSAL](https://github.com/Azure/azure-cli/pulls?q=label%3A%22Azure+Identity+Adoption%22), we should make sure concurrent accesses are handled correctly.